1995 GMC Sonoma Owner's Manual - Page 76

Hectronic Transfer Case If your four-wheel drive vehicle has the electronic transfer case, the transfer case switches are on the right side of your instrument panel above the radio controls. Use these switches to shift into and out of four-wheel drive. You can choose among three driving settings: 2HI - This setting is for driving in most street and highway situations. Your front axle is not engaged in two-wheel drive. 0 4J3I - This setting engages your front axle to help drive your vehicle. Use 4HI when you need extra traction, such as on snowy or icy roads, or in most off-road situations. 4LO - This setting also engages your front axle to give you extra traction. You may never need 4LO. It sends the maximum power to all four wheels. You might choose 4LO if you were driving off-road in sand, mud, deep snow and climbing or descending steep hills. Amber indicator lights in the switches show you which setting you are in. The indicator lights will come on briefly when you turn on the ignition and one will stay on. If the lights do not come on, you should take your vehicle in for service. When shifting, an indicator light will flash until the shift is completed then remain solidly lit. 0 To shift from2HI to 4HI- Press and release the 4HI switch. This can be done at any speed, and the front axle will lock automatically. To shift from 4HI 2HI - Press and release the 2HT switch. This can be to done at any speed, and the front axle will unlock automatically. To shift from 2H1, or 4HI to 4LO - The vehicle must be stopped or moving less than 3 mph (4.8 km/h) with the transmission in NEUTRAL (N) in vehicles equipped with an automatic transmission or the clutch pedal depressed in vehicles equipped with a manual transmission. The preferred method for shifting into 4LO is to have your vehicle slowly moving 1 to 2 mph (1.6 to 3.2 k d h ) . Press and release the 4LO switch. You must wait for the amber 4LO indicator light to stop flashing and go solid amber before shifting your transmission into gear or releasing the clutch pedal. 2-30